Switch-operating mechanism



June, 24, 1930. c. F.CARPENTER swn'c'n OPERATING MECHANISI Filed April'13. 1928* W Inventor-z Charles F'Ca #065 His Attorneg. I

Patented June 24, 19301 UNITED ST TES PATENT orrlca CHABLES I.CARPENTER, OI AIDY, NEW YORK, ASSIGNOR TO GENERAL ELEC- TRIO comm, AOOBP OBATIOH 01' NEW YORK SWITCH-OPERATING IECKANISH Application fledApril 13,

My invention relates to electric switches and more particularly tooperating mechanism there or. I

Although it obviously has other applicaul in 6 tions, my invention isparticularly use connection with controlling apparatus for electricmotors.

A great majority of certain types" of electric motors as for instance,squirrel cage in- 1 duction motors, are started by connecting them to areduced primary volta during the starting interval, the redu primaryvoltage beingobtained by the use of transformer methods or by the use ofprimary resistances. After-a certain time interval has elapsed to allowthe motorto accelerate, the motor is directly connected to the full linevoltage. Starters comprising-switches having two sets of contacts areordinarily provided, first, to connect the motor to the remf ing handleor lever and it is very desirable in as the contacts touch, andtherefore ny'invention in one of its aspects contemplates the provisionof a switchin mechanism, the contacts of which are positively forcedinto a mechanical and electrical engagement without the necessity ofemploying excessive actuating forces.

Controllers provided with two such sets of contacts are generallyoperated by a startstoppin the motor that when the handle is moved m therunning position at which full voltage is applied to the motorto theneutral position it does not or is not swung past the neutral positionto the starting posi tion at which low voltage is applied to "the motor.Another aspect of my invention is the provision of a starting mechanismof the type utilizing two sets of contacts and an operating levertherefor'in which the lever is me. semi 10. 20am.

preventing rapid movement" of the actuating mechanism from the runningto the starting position.

For a more complete understanding of my,

invention reference should be had to the accompanying drawing in whichFigure 1 is a perspective view of the switching mechanism with portionsbroken awa to illustrate certain structural details; igure 2 is a frontelevation ofthe switching mechanism showing it in its starting position;Figure 3 is a front elevation of the switching mechanism showing it inits running position; and F1gure 4 is a detail of a portion of thelatchm mechanism.

ferring to the drawing, I have shown my invention in one form as appliedto a motor controller in which two sets of contacts are employed, oneset for connecting the motor to a low voltage source and one set forconnecting the motor to a high voltage source. As shown, a suitableframework 10 is provided for supporting a platform or plate 11 to whichthe elementsthat make up the switching mechanism are attached. Two

sets of stationary contacts 12 and 13 are pro I vided, the contacts 12leading to a source of low voltage, and the contacts 13 leading to asource of higher voltage. Two sets of movable contacts 12" and 13 areprovided for engaging the contacts 12 and 13 respectively w ereby thecircuits may be comletedfrom the voltage sources of the motor. it willbe understood that the numberof contacts in each set depends upon thetype of motor to be controlled and upon the method employed to obtainthe reduced voltage. For instance, in controlling a three p aseinduction motor where the reduced voltage is secured by the use of atransformer, five pairs 0 starting contacts 12 and 12" are providedforconnecting the moloo tor to the low voltage source and three pairs ofrunning contacts 13 and 13 are provided for connecting the motor to thehigh voltage source. A contact supporting member or switch arm 14 isprovided, the switch arm having two sets of spaced arms 15 and 16 towhich the move is contacts 12 and 13 are respectively pivoted. The lowerportion of the contact carrying member 14 is provided with rigid crossmember 17 between the ends of which and the movable contacts 12 and areinserted springs 18, this construction permitting the contacts to beswung about their pivots relative to the switch arm 14 as they move intoengagement with their cooperating stationary co tacts.

An insulated shaft 20 suitably supported at each end from the plate 11,as by means of a bearing member 21, is provided for rotatabiy supportingthe switch arm 14. A fever member 23 is rigidly secured to the shaft 20and mechanism cooperating with the lever 23 is provided for biasing theshaft 20 to its neutrai position, that is, the position in which bothsets of contacts are held out of engagement. As shown two levers 24 and25 are pivoted to the bearing bracket 21, these members being disposedon opposite sides of a crank arm 23 projecting from the lower end of thelever 23. A tension spring 26 is connected at its ends to each of the-levers 24 and 25, thereby urging the levers towards each other.Suitable pins 27 mounted upon the bracket 21 limit the inward positionto which these levers may be swung. Thus, it will be observed that inthe absence of any actuating force upon the lever 23, the lever will beheld in its neutral position by the spring actuated levers.

Suitabie operatingtmechanism is provided for causing the sha 20 torotate within its bearings whereby either set of the movable contacts12- or 13 may be moved into engagement with its corresponding set ofstationary contacts. As shown, the actuating mechanism comprises arotatable shaft 30 mounted upon the plate 11, the shaft 30 carrying anactuator or lever 32 keyed thereto and depending therefrom. The actuator32 at its lower end is provided with a pair of spaced arms 33 whichpivotally support a roller 34 between them. The upper end of the lever23 is provided with a fork 35 comprising, as shown, a pair of oppositelydisposed surfaces, which in any position of the lever, embrace theroller 34. Thus, it will be observed that upon swin ing motion beingimparted to the depen in lever 32 in either direction, the lever 23 anconsequently the shaft 20 are caused to rotate in one direction or theother as the case may be. Obviously the roller 34 may be eliminated anda stationary follower member substituted therefor, the roller howeverbeing provided to reduce .wear to a minimum. It will be further observedthat as the levers 23 and 32 move from their aligned position, that theleverage between the two gradually increases, so that the force withwhich either set of the contacts 12 or 13 is moved into engagement withits corresponding set of stationary contacts increases gradually as thelevers are so moved. In some cases it is desirable that the change ofleverage be accentuated at the moment the contacts touch so that theforce urging them together be increased, the fork 35 therefore isprovided at its outer ends with flared surface 36, these surfaces beingarranged at such an angle with the parallel surfaces 3? as to transmitthis desired increase of which the roller 34'is adapted to engage.

Obviously the fork 35 may be designed to cause this abrupt change inleverage at any particular point in the path of movement of either ofthe moving contacts, and furthermore may be designed to cause a force ofgreater or less degree within wide limits to be applied to the movingcontact. Any suitable means may be provided for rotating the shaft 30whereby motion is in turn transmitted to the shaft 20, for example, ahand operated lever or handle 38 may be employed for this purpose.

In order that the lever 38 may not be initially moved from its neutralto its running position, suitable latching means is provided therefor.This latching means comprises a member 40 pivotally mounted upon theplate 11 and provided with two arced shaped recesses 41 and 42. Asuitable member 43 is mounted upon the shaft 30 for cooperating with thelatch 40. This member as shown is provided with 9. rectangular borecorresponding in cross section with that of the shaft 30 whereby it iskeyed thereto. One end of the member 43 is provided with a projectingarm 45 and the other end is provided with a projecting plate 46, the arm45 and the plate 46 forming bearing members for a pin 47 which is ofsuch proportions that it may be engaged by either of the recesses 41 or42 -within the latch 40. When the handle 38 is in its neutral position,as shown in Figure 1, the notch 41 engages the pin 47 preventing ahymovement ofthe lever 38 toward the left as viewed in Figures 2 and 3,that is, toward the running ition, but allowing movement towards t eright as viewed in those figures, that is, toward the starting position,because of the gradually inclined edge 41 of the recess, clearly shownin Figure 4. The lever 38, however, may be rapidly moved from thestarting to the running position without interference by the latchingmember 40. It will be understood thatthe latch 40 due to its inertiafalls with sufficient rapidit to cause'its notch 41 to enga e the pin 47uring the rapid movement 0 the lever 38 from starting to runningposition. Thus, it will be observed that although the starting membermay not be moved initially from the neutral to the running position itmay be thrown directly from the starting to the runni position providedthis movement is e ected at high speed. \Vhen the lever 38 is in itsrunning position thepin 47 rests within the recess 42 of the latchingmember 40.

toggle so that-it may be ali of the lever from neutral to starting leverhas been moved into its running rgized b Suitable lockin means isprovided for the latch 40 so t at the lever 38 may be securely locked inits running position. As

shown, the locking means comprises a tog-.

it as the arm 50 is swung about the fixed pin Y 49 in a counterclockwisedirection, as viewed in Figures 2 and 3. An electromagnet 52 is operablyconnected to the arm 50 by means of links 53 and 54 so that when themagnet is 'deenergized the arm is moved. about its pivot to break thetoggle and when the ma net is energized the arm is withdrawn %rom thepath of movement of the gned. It will be observed that when the lever 38is in its neutral or starting position, the toggle will be brokenwhereby unobstructed movement P091 t1on and thence to runni mitted.However, when t e lever 38 is in its running ition, the toggle 48 willbe aligned, as sii svn in Figure 3, thereby venting any upward movementof the 40. It will be understood that after the tion, the magnet 52 willbe ene y some means either automatically or manually actuated so thatthe toggle m then ali 11 itself to lock the lever 38. Wlnen it is esiredto move the lever 38 to its neutral position, the m net is deenerginedand the to gle thereb broken. The lever 38 may t en be rea ily moved toits neutral position, the latch 40 permi unobstructed movement becauseof the gradually inclined edge 42' of the notch 42.

A latching mechanism is also provided for preventing rapid movement ofthe lever 38 from the running position through the neutral to thestarting position, this latching mechanism however, rmitting the lever38 to be moved slowly t rou h the neutral position. This latching mecanism comprises a latch 56 pivoted at a point near its center to theplate 11 and provided with a U shaped recess 57 in its forward end, the

runni the switch in its neutral positionf position is perrecessaccommodating the pin 47 and being of sufiicient depth to allow thelever 38 to be fully moved to its starting position. A pin 58 supportedbetween the arm 45 and the plate 46 serves to engage the latching member56 as the lever 38 is moved to its position, thereby raising the latchupwar ly and holding it out of engagement with the pin 47. When thelever 38 18 mp idly moved from its running position toward its startingposition through the neutral point, the pin 47 instead of being receivedwithin the recess 57 engages the end of the lower leg 59 of the U shapedrecess, whereby further movement in that direction is arrested afterwhich the latch falls to a position which does not interfere withfurther motion of the lever. the lever 38 be moved slowly through itsneutral position, the bar 56 will slowly follow the in 58 in itsdownward movement and receive the pin'47, permitting uninterruptedmovement of the lever 38 in this direction, the elongated upper leg 59of the U shaped recess resting upon the pin 47 during this movement. Itwill be understood that the pin 58 is so positioned upon the plate 46relative to the pin 47, and that the inertia of the latch 56 as governedby its mass and the osition of its pivot adjacent to its center is such,that the latch cannot rapidly follow the pin 58 in its .downwardmovement when the lever 38: is quickly moved. Thus, the latch functions"to provided it is being moved at ahigh rate 0 speed, consequent!preventing any danger of overtravel 0 the switching member.

In operation of the starting device, the lever 38 is moved from itsneutral sition shown in Figure 1, toward its starting po- However,should I sition, that is, toward the right as viewed 7 in Figures 1 and3, imparting motion to the lever 32 and con uently to the shaft 20. Asthe shaft 20 is t us rotated, the moving contacts 12. are moved towardtheir stationary contacts 12, the force by which they are i moved intoengagement increasing rapidly because of the peculiar shape given to thel e ork member cam surfaces provided on 35. 'The lever 38 is then movedtoward the left as viewed in Figures 2 and 3, through its neutralposition and over to its running position, the contacts 13' likewisebeing moved forcibly into engagement with their stationary contacts 13,in which position the switching mechanism is locked by the interandperhaps cause engagement between the starting contacts, which action isprevented by the latch 56, which precludes any such rapid movement ofthe lever 38 through its neutral position.

While I have described my invention as embodied in concrete form and asoperating in a specific manner in accordance with the provisions of thepatent statutes, it should be understood that I do not limit myinvention thereto since various modifications thereof will suggestthemselves to those skilled in the art without departin from the spiritof my invention the scope c which is set forth in the annexed claims.

\Vhat I claim as new and desire to secure by Letters Patent ot theUnited States is:

1. A switch comprising, a plurality of stationary contacts, a pluralityof movable contacts cooperating with said stationary contacts, anoperating member for said movable contacts provided with a plurality ofcams, one for each of said movable contacts, and an actuator member forselectively engaging said cams so as to cause said operat ing member tomove the corresponding movable contact into engagement with itsstationary contact.

2. A switch comprising, a stationary contact and a movable contact, alever operably connected to said movable contact and having a camsurface thereon, means biasing said lever to normally maintain saidmovable contact out of engagement with said stationary contact, andmeans for engaging said cam surface for causing movement of said movablecontact, said cam surface being arranged to cause aforce of increasingmagnitude to be applied to said movable contact as the contacts moveinto engagement.

3. A motor controllin mechanism comprising, low voltage and ull voltagestationary contacts, movable contacts for cooperating therewith, a leveroperably connected to said movable contacts for causing interengagementof either the low or high voltage contacts upon movement of said leverin one direction or the other, means biasing saidlever to a neutralposition, and means for causing said lever to moi e in one direction orthe other against said biasing means with a force of increasingmagnitude.

4. A switch comprising, a stationary contact and a movable contactcooperating therewith, a switch arm supporting said movable contact, ashaft upon which said switch arm is mounted, an actuating shaft forimparting motion thereto, and means for transmitting motion from saidactuating shaft to said first mentioned shaft arranged to cause saidmovable contact to be moved with a force of increasing magnitude as itengages said stationary contact.

5. A switch comprising, a stationary contact and a movable contact forcooperating therewithfa pivoted switch arm carrying said movablecontact, a lever operably connected to said switch arm and having a camsurface at one end thereof with a portion parallel to the length of saidlever and a portion disposed at an angle thereto, and an actuator forengaging said cam surface whereby said contacts are caused to move intoengagement with a force of increasing magnitude.

6. A motor controlling mechanism comprising, low voltage and fullvoltage sta tionary contacts, movable contacts for cooperatingtherewith, a lever operably connected to said movable contacts andhaving opposed cam surfaces at one end thereof, an actuating leverhaving a portion disposed between said cam surfaces whereby said leverupon being moved in one direction causes interengagement of said lowvoltage contacts and upon being moved in the opposite direction causesinterengagement of said full voltage contacts.

7. A controlling device comprising, an arm movable in either directionfrom a normal position of rest, and gravity actuated means forpreventing rapid movement of said arm in one direction throu 11 itsposition of rest but permitting rapi movement therethrough in theopposite direction.

8. A controlling device comprising, a lever having a normal position ofrest, gravity actuated latching means for said lever, and means.operated by said lever for controlling the movement of said latchingmeans whereby said lever is prevented from being rapidly moved in onedirection through its position of rest.

9. controlling device comprising, a lever having a neutral position, anda gravity actuated latching member therefor pivoted adjacent said leverand controlled by the motion thereof, said latching member permittinguninterrupted movement of said lever in one direction and engaging saidlever to limit its movement in the opposite direction when said lever ismoved with a predetermined speed.

10. Motor control means comprising, switching means movable in oppositedirections from a neutral position to starting and running positions,means for biasing said switching means to said neutral ition, latchingmeans for holding said switching means in said running position inopposition to its bias, and gravity actuated means for preventingmovement of said switching means through the neutral ition to thestarting position when said atching means is released.

11. A control device comprising, a lever having a neutral position, apin' mounted upon said lever, a gravity actuated latch provided with a.U-shaped recess in one end thereof pivoted adjacent said lever, and

means carried by said lever for controlling the movementof said latchwhereb when said lever is slowly moved toward its neutral position saidpin is received within said U-shaped recess permitting unobstructedmovement of the lever and whereb when said lever is rapidly moved towardits neu- I tral position said pin is engaged by a leg of the U-sha edrecess preventing continue movement 0 the lever.

In witness whereof, I have hereunto set my hand this 12th da of A ril,1928. 1 CHARLE FL ARPENTER.

